interrupts are disabled on reset

software/software.ino

@@ -0,0 +1,70 @@
+#include "Keyboard.h"
+#include "HID.h"
+
+#if F_CPU == 16000000
+#error should be running at 8MHz
+#endif
+
+#define PIN A0
+
+void goto_bootloader() {
+    cli();
+    UDCON |= (1<<DETACH);
+    USBCON |= (1<<USBE);
+
+    TIMSK0 = 0;
+
+    MCUCR |= (1<<IVCE);
+    MCUCR |= (1<<IVSEL);
+    asm("jmp 0x7000");
+}
+    
+
+void check_blcmd() {
+    if (Serial.available()) {
+        String in = Serial.readStringUntil("\n");
+        if (in.equals("bootloader\n")) {
+            goto_bootloader();
+        }
+    }
+}
+
+void toggle() {}
+
+void turned_on() {
+    Keyboard.press(KEY_F15);
+    Keyboard.releaseAll();
+}
+
+void turned_off() {
+    Keyboard.press(KEY_F14);
+    Keyboard.releaseAll();
+}
+
+void setup() {
+    pinMode(PIN, INPUT_PULLUP);
+    Keyboard.begin();
+    Serial.begin(9600);
+    Serial.setTimeout(50);
+}
+
+
+void loop() {
+    static bool last_state = 0;
+
+    bool current_state = digitalRead(PIN);
+
+    if (last_state != current_state) {
+        toggle();
+        if (current_state)
+            turned_on();
+        else
+            turned_off();
+        last_state = current_state;
+    }
+
+
+    check_blcmd();
+    delay(100);
+
+}